For a particular scientific experiment, it is important to be completely isolated from any magnetic field, including the earth's field.

For a particular scientific experiment, it is important to be completely isolated from any magnetic field, including the earth's field. A 1.50m-diameter current loop with 220 turns of wire is set up so that the field at the center is exactly equal to the earth's field in magnitude but opposite in direction. What is the current in the current loop?I=________A